Inhibitory Effect Of Zuojin Pills Combined With EGFR-targeted Polypeptide MM2 In Intestinal Cancer

Objective:In recent years,with the discovery of EGFR function and the upgrade of tyrosine kinase inhibitors,drugs targeting EGFR for anti-tumor present clear efficacy and have been widely used in clinic.However,the mutation of the EGFR gene will change with the occurrence and progression of cancer cells,which limits the use and function of drugs.This study aims to screen a novel polypeptide MM2 that can antagonize EGF and target EGFR competitively by polypeptide synthesis,and to investigate its anti-tumor effect.Our previous study has found that Zuojin pills can inhibit the activation of PI3 k downstream of the EGFR signaling pathway and enhance the efficacy of chemotherapeutic drugs.This study aims to investigate the inhibitory effect and its mechanism of Zuojin pills combined with MM2 in intestinal cancer.Methods:1.Based on Tenta Gel resin,novel polypeptides were synthesized under room temperature using one bead-one compound cyclic-peptide and segmentation method.2.Polypeptides binding to EGFR were screened by immunofluorescence.3.The affinity between polypeptides and EGFR protein was detected by the fluorescence polarization technique.4.A mouse model of subcutaneous transplanted tumor was established by subcutaneous injection with HCT-8 cells.The volume of tumors and the weight of nude mice were measured regularly,and the effects of MM2 on the quality of life and growth of tumors in mice were observed.5.The regulatory effect of synthesized polypeptide MM2 in tumor cells on EGFR phosphorylation and the effects of MM2 on the phosphorylation of Ak T and ERK genes downstream EGFR were detected using Western blot.6.The effect of MM2 on the proliferation of colorectal cancer cells was determined by CCK-8 assay and monoclonal technology of cancer cells.7.The effects of MM2 on the invasion and migration of colorectal cancer cells were determined by Transwell assay and wounding healing assay.Results:A novel polypeptide MM2 was obtained by one bead-one compound cyclic-peptide.It could specifically bind to EGFR and inhibit the phosphorylation of EGFR and its downstream genes AKT and ERK.MM2 could inhibit the proliferation of KRAS wild-type colorectal cancer cells,and the invasion and metastasis of colorectal cancer cells.The statistical data of tumor size showed that MM2 significantly inhibited the growth of subcutaneous transplanted colorectal cancer cells in nude mice.After combining with Zuojin pills,its anti-tumor effect was further enhanced.Zuojin pills combined with MM2 could reduce the phosphorylation of EGFR-related downstream genes AKT and ERK.Conclusion:One bead-one compound cyclic-peptide is a stable and efficient method for chemical synthesis of polypeptides.A novel polypeptide MM2,which can specifically bind to EGFR,is screened.MM2 can inhibit the conduction of the downstream PI3K-AKT and MAPK/ERK signaling pathways,and inhibits the proliferation,invasion and metastasis of colorectal cancer through inhibiting EGFR phosphorylation.In addition,it is found that Zoujin pills combined with MM2 enhances the anti-tumor effect of MM2.